Method and device for enhancing the reduction of pathogens, allergens and odor-causing agents

ABSTRACT

Disclosed are methods and apparatus that help reduce and prevent infection by controlling and/or reducing the level of contaminants, which include pathogens, allergens and/or odor-causing agents including VOCs. Photocatalytic oxidation is performed in a high humidity environment so that hydrogen peroxide molecules are readily produced.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/446,825, filed Mar. 1, 2017 and titled “Method and Device forEnhancing the Reduction of Pathogens, Allergens and Odor-CausingAgents,” the entirety of which is incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to devices and methods for controllingand/or reducing the level of one or more pathogens, allergens and/orodor-causing agents in a closed or semi-closed environment.

BACKGROUND

Pathogens, allergens and odor-causing agents, including pathogenicmicrobes, molds, mildew, spores, and organic and inorganic pollutants,are commonly airborne or on contact surfaces in a wide range ofenvironments. These substances can cause discomfort and, in somesituations, serious illness and death to those who inhale or come incontact with them.

Microbial control and disinfection in environmental spaces is generallydesirable because it improves the cleanliness and healthiness of thearea. Additionally, disinfection of the air and surfaces associated witha medical clean room, an operating room, a food processing environment,certain types of pharmaceutical or bio labs and the like is a necessity.Numerous techniques, devices and procedures have been used to disinfectspaces and areas in order to purify air and disinfect surfaces initiallyand to keep them disinfected for extended periods of time. Many of theseknown techniques, devices and procedures are complex, cumbersome,expensive and relatively ineffective over the long term.

For example, it is known that Reactive Oxidizing Species (“ROS”), whichare chemically reactive molecules containing oxygen such as thoseproduced by a photocatalytic oxidation processes, are able to oxidizeorganic pollutants and kill microorganisms on contact. Moreparticularly, the products of photocatalytic reactions, such as hydroxylradicals, hydroperoxyl radicals, chlorine, hydrogen peroxide, and ozone,are known to be capable of oxidizing organic compounds and killingmicroorganisms. There are, however, existing limitations to the alreadyknown methods and devices available to those skilled in the art. Theexisting limitations are due to both their limited efficiency as well asbecause of potential human safety issues. “ROS” is a term often used todescribe highly activated molecules created in air that result fromambient humid air being exposed to a specific bandwidth of ultraviolet(UV) light.

With respect to the use of UV light alone, light or radiation in theultraviolet range (i.e. 10-400 nm) emits photons at a frequency that hassufficient energy to break chemical bonds when absorbed certaincompounds. UV light at wavelengths between 250-255 nm is routinely usedas a biocide. UV light between about 181 nm to about 187 nm is oftenused to break down certain molecules found in air in order to produceozone. UV light can also be used in certain circumstances to produceozone. Production of ozone using UV light is often a method that iscompetitive with an electrical corona discharge technique that is alsoused to produce ozone.

UV radiation and ozone are both sometimes used to disinfect communitywater systems. Ozone is known to be used to help disinfect and treatindustrial wastewater and water cooling towers.

Hydrogen peroxide is also known to have antimicrobial properties and hasbeen used in aqueous solution for disinfection and microbial control.

Many attempts to disinfect air within a room by using hydrogen peroxidein its gas or vapor phase have been made. However, the attempts havebeen hampered by technical hurdles associated with the desire to produce“purified” hydrogen peroxide. More particularly, vaporized aqueoussolutions of hydrogen peroxide generally produce an aerosol of microdroplets composed of aqueous hydrogen peroxide solution.

Various processes for “drying” vaporized hydrogen peroxide solutionsproduced a hydrated form of hydrogen peroxide that was not very useful.The hydrated hydrogen peroxide was determined to be undesirable becausethe hydrated hydrogen peroxide molecules were surrounded by watermolecules bonded by electrostatic attraction and/or London Forces. Itwas further determined that the ability of the hydrogen peroxidemolecules to interact directly with the environment via an electrostaticforce was greatly attenuated by the water molecules bonded to thehydrogen peroxide molecules. Accordingly, past efforts have beendirected at reducing or eliminating the water molecules being bonded tothe hydrogen peroxide in order for the hydrogen peroxide molecule to beable to interact with, react with and disinfect organic pollutants andmicroorganisms.

Additionally, an important drawback of using vaporized hydrogen peroxideis that the concentrations needed and created were generally well abovethe 1.0 ppm OSHA workplace safety limit. Thus, using vaporized hydrogenperoxide to disinfect organic pollutants and to kill microorganisms isunsuitable for use in work areas or environments that are occupied byworkers.

Photocatalysts have been used in the past to reduce or eliminate organicpollutants in fluid. Such photocatalysts include, but are not limitedto, TiO2, ZnO, SnO2, WO3, CdS, ZrO2, Sb2O4 and Fe2O3. Of these, titaniumdioxide (TiO2) is chemically stable, has a suitable bandgap forUV/Visible photoactivation, and is relatively inexpensive. Thephotocatalytic chemistry of titanium dioxide has therefore been theobject of extensive studies over the past thirty years for its abilityto reduce or eliminate organic and/or inorganic compounds that arehazardous to humans from contaminated air and water.

Photocatalysts have been used to produce hydrogen peroxide gas forrelease into an environment, because the photocatalysts also generatehydroxyl radicals inexpensively from water when activated by UV light ofsufficient energy. Prior uses of photocatalysts, however, have primarilyfocused on the generation of plasma containing many different reactivechemical species. Further, the majority of the chemical species in thephotocatalytic plasma are reactive with hydrogen peroxide, and thereforeinhibit the production of hydrogen peroxide gas due to the simultaneousreactions that also destroy or tear down hydrogen peroxide molecules.Also, since hydrogen peroxide is a very reactive molecule, any organicgases that are introduced into the plasma inhibit hydrogen peroxideproduction both by direct reaction with hydrogen peroxide and byreaction of their oxidized products with hydrogen peroxide.

Photocatalytic reactors themselves also limit the production ofvaporized hydrogen peroxide for release into the environment. This isdue to the fact that hydrogen peroxide has greater chemical potentialthan oxygen to be reduced as a sacrificial oxidant. Thus, inphotocatalytic reactors, hydrogen peroxide is preferentially reducedback to hydrogen and oxygen as it moves downstream, within a reactor, asrapidly as the hydrogen peroxide is produced by the oxidation of water.

Oxidation:

2 photons+2H2O→2OH+2H+2e−→H2O2

Reduction:

2OH+2H+2e−→2H2O

Additionally, several side reactions generate a variety of species thatbecome part of the photocatalytic plasma and inhibit the production ofhydrogen peroxide gas that can be released into an environment.

The wavelengths of light that activate photocatalysts are energeticenough to weaken or break the peroxide bond in a hydrogen peroxidemolecule and inhibit the production of vaporized hydrogen peroxide thatcan be released into an environment. Further, the practice of usingwavelengths of light that produce ozone introduces yet another speciesinto the photocatalytic plasma that destroys hydrogen peroxide.

O3H2O2→H2O+2O2

In practice, the use of photocatalysts has focused on the production ofplasma, often containing ozone, which is then used to oxidize organiccontaminants and microbes. Since these plasmas are primarily onlyeffective within the confines of the reactor itself, these devices aredesigned to pass only air through the reaction chamber for disinfection.See, for example, U.S. Pat. No. 6,955,791. As such, they are of limiteduse in disinfecting either large spaces or the surfaces of objects.

The plasmas also have a limited chemical stability beyond the confinesof the reactor where they were created and further actively degradehydrogen peroxide gas therein.

Furthermore, since with this prior design, the plasma is only reallyeffective within the confines of the reactor itself, many prior designstry to maximize the residence time of the “contaminated air flow” withinthe reactor in order to facilitate a more complete oxidation of organiccontaminants and microbes as they pass through the reactor. But, sincehydrogen peroxide has such a high potential to be reduced, the maximizedresidence time concomitantly results in a minimized hydrogen peroxideproduction resulting in an ineffective decontamination device.

Also, most uses of photocatalysts produce environmentally objectionablechemical species. The first objectionable chemical species among theseis ozone itself, which is an intentional product of many systems. Ozone,however, is potentially harmful when inhaled by humans and ozone levelsthereof are strictly regulated.

Moreover, since organic contaminants that pass through a reactor areseldom oxidized in a single exposure, multiple air exchange devices maybe necessary to achieve full oxidation of organic contaminants andmicrobes to carbon dioxide, water and other non-organic contaminants.When incomplete oxidation occurs, various aldehydes, alcohols,carboxylic acids, ketones, and other partially oxidized organic speciescan be produced in the reactor. Often, prior photocatalytic reactors canactually increase the overall concentration of organic contaminants inthe air by fractioning large organic molecules into multiple smallorganic molecules, such as formaldehyde.

Other prior attempts to use ozone and hydrogen peroxide for disinfectionhave sought to control the temperature and humidity of the environmentbeing cleaned. For example, U.S. Pat. No. 7,407,624 discloses a methodfor abating allergens, pathogens, odors and volatile compounds in asealed enclosure using specific concentrations of ozone and hydrogenperoxide in the sealed environment at a specific temperature andspecific humidity. This method, however, is not practical for use in anarea the size of a room, such as a medical surgery room because of theneed to seal the environment being disinfected and because the levels ofozone are far too high for human safety.

As such, there remains a need in the art for an effective method ofcontrolling and/or reducing the level of one or more pathogens,allergens, organic or inorganic pollutants, and/or odor-causing agentsfrom the air and surfaces in an environment where humans live or work.

SUMMARY

Embodiments of the invention provide a system and method that helpscontrol or reduce the level of one or more pathogens, allergens and/orodor-causing agents within a defined area or environment such as a room,a building, a surgery room, a locker room, a nursery room, a kitchen, abath/shower room, a laboratory, an airplane, train, boat, bus, car orother transportation vehicle cabin, a sauna, an HVAC system, and otherclosed or semi-closed areas or environments where humans work or live bycreating combinations of ozone and hydrogen peroxide within a reactionchamber and discharging the ozone, hydrogen peroxide and other createdmolecules such as hydroxyl radicals and super ions as part of a humidvapor into the defined area or environment.

Various embodiments are directed to a method for controlling and/orreducing the level of a substance or contaminant selected from the groupconsisting of a pathogen, an allergen and an odor-causing agent,comprising: exposing the substance to a gaseous atmosphere comprising aneffective amount of ozone and hydrogen peroxide, wherein the hydrogenperoxide is generated in an environment having a relative humidity of atleast 70% to 100%. The substance is exposed to this gaseous atmospherefor a time period sufficient to abate the substance being targeted.

Other embodiments are directed to devices for generating a gaseousatmosphere comprising an effective amount of ozone and hydrogenperoxide, wherein the hydrogen peroxide is generated in an environmenthaving a relative humidity of 70% to 100%.

Some embodiments provide a system that reduces a level of substances inair within an environment, wherein the environment comprises a closed orpartially open environment and wherein the substances are selected fromthe group consisting of pathogens, allergens and odor-causing agents.These embodiments comprise an inlet passage configured to receive inletair from the environment, the inlet air comprises an initial level thesubstances. There is also a humidifier input configured to receive watervapor from a humidification device and a mixer portion where the inletair and water vapor are mixed, the mixer portion outputs an air/vapormixture having a humidity between 75 and 100 percent.

Such embodiments further include a treatment chamber wherein theair/vapor mixture is subject to a photocatalytic oxidation treatment.The treatment chamber includes a plurality of active cell panels,wherein, the active cell panels have at least a portion of theirsurfaces coated with photocatalytic material; one or more ultraviolet(UV) light sources interspersed between the plurality of active cellpanels such that UV light emitted from the one or more UV light sourcesimpinges on photocatalytic material; wherein the combination of the oneor more active cells, the one or more ultraviolet light sources and theair/vapor mixture are adapted to generate between about 0.0001 and0.0070 ppm ozone, between about 0.25 and 0.45 ppm hydrogen peroxide, andhydroxyl radicals and super ions that oxidize or decompose thesubstances such that the substance level in the treatment chamber isreduced.

There is also a humidity sensor positioned between the mixer portion andan output of the treatment chamber. The humidity sensor is configured tosense the humidity level of the air/vapor mixture and to provide afeedback humidity signal for controlling the humidification device.

Additionally, the embodiments include an outlet passage configured toallow treated air/vapor to exit the treatment chamber and be distributedinto the environment wherein a residual amount of the ozone, hydrogenperoxide, hydroxyl radicals, and super ions continue to oxidize ordecompose substances in the air or on surfaces within the environmentuntil the residual amounts of ozone, hydrogen peroxide, hydroxylradicals, and super ions disassociate.

In various embodiments, at least one of the active cells comprises aplurality of apertures disposed in a transverse manner from a first sideof the active cell to a second side of the active cell. The surfaces ofthe apertures are coated with the photocatalytic material.

In additional embodiments, the plurality of apertures are furtherconfigured to direct air/vapor mixture away from or toward the UV lightsources as the air/vapor mixture moves from the inlet passage toward theoutlet passage.

In some embodiments the blower that is proximate to the inlet passage isfor pushing inlet air from the environment exterior to the embodimentand into the inlet passage toward the treatment chamber.

In various embodiments the mixer portion comprises a static mixer.

In yet other embodiments, one or more of the ultraviolet light sourcesextend from a side wall of the treatment chamber and in between activecell panels.

In yet additional embodiments, the active cell panels are positionedapproximately parallel with each other.

In other embodiments, the humidification device is configured to providewater vapor to the humidifier input such that the humidity of theair/vapor mixture is maintained within a predetermined range.

In yet additional embodiments, the average velocity of air/vapor withinthe treatment chamber is between 5 and 100 times slower than the averagethe average outlet passage treated air/vapor velocity.

In additional embodiments, the treatment chamber further comprises anairlock configured to allow the introduction and removal of an object tobe treated for decontamination.

In yet other embodiments, the heater is configured to heat the inlet airto a temperature high enough such that the water vapor mixed with theinlet air will not become saturated or condensate within the embodiment.

Another embodiment provides a method of reducing a substance level inair within an environment, wherein the environment comprises a closed orpartial open environment and wherein the substance level comprisessubstances selected from a contaminate group consisting of pathogens,allergens and odor-causing agents. The method comprises receiving airfrom the environment into an inlet passage; mixing the received air withwater vapor to achieve a 75 to 100 percent humidity air/vapor mixture;treating the air/vapor mixture in a treatment chamber, wherein treatingcomprises: impinging, by an ultraviolet light source, ultraviolet lighton photocatalytic surfaces within the treatment chamber and on theair/vapor mixture within the treatment chamber to produce between about0.0001 and 0.0070 ppm ozone, between about 0.25 and 0.45 ppm hydrogenperoxide along with hydroxyl radicals and super ions that oxidize ordecompose the substances such that the substance level in the treatmentchamber is reduced.

The exemplary method further comprises outputting the treated air/vapormixture back into the environment such that residual amounts of theozone, hydrogen peroxide, hydroxyl radicals, and super ions continue tooxidize or decompose substances in the air or on surfaces within theenvironment until the residual amounts of ozone, hydrogen peroxide,hydroxyl radicals and super ions disassociate.

In additional embodiments of the method, the treatment chamber comprisesa plurality of active cell panels having surfaces coated with thephotocatalytic material. Furthermore, the active cell panels extend froma treatment chamber sidewall into the treatment chamber.

In other embodiments of the method, the active cell panels comprise aplurality of apertures disposed in a transverse manner from a first sideto a second side of each of the active cell panels.

In yet other methods, the ultraviolet light source is positioned betweenand adjacent to two active cell panels.

In additional embodiments, the method further comprises heating theintake air from the environment prior to mixing such that the watervapor mixed with the air from the environment will not become saturatedor condensated.

In yet other methods, outputting the treated air/mixture furthercomprises outputting air, benign contaminates, a reduced level ofsubstances, less than 0.0007 ppm ozone, less than 0.45 ppm hydrogenperoxide, between 75 and 100 percent humidity, hydroxyl radicals andsuper ions.

In various methods, the odor-causing agents are selected from the groupconsisting of smoke, engine exhaust and volatile organic compounds.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory onlyand are intended to provide further explanation of the invention asclaimed.

BRIEF DESCRIPTION OF THE DRAWINGS

Various objects, features, characteristics and advantages of theinvention will become apparent and more readily appreciated from thefollowing description of the embodiments, taken in conjunction with theaccompanying drawings and the appended claims, all of which form a partof this specification wherein like reference numerals designatecorresponding parts in the various figures and wherein the variouselements depicted are not necessarily drawn to scale; and wherein:

FIG. 1 is a block schematic diagram of an embodiment of an apparatus forreducing pathogens, allergens, and odor-causing agents from a closed orsemi-closed environment;

FIG. 2 is a schematic diagram of another embodiment of an apparatus forreducing pathogens, allergens, and odor-causing agents from a closed orsemi-closed environment;

FIG. 3 is a schematic diagram of another configuration of an embodimentof the invention;

FIG. 4 is a perspective view of an active cell in accordance with anembodiment of the disclosure; and

FIG. 5 is a flow diagram of a method of reducing contaminants from airin a closed or semi-closed environment in accordance with embodiments ofthe disclosure.

DETAILED DESCRIPTION

The following description and examples illustrate a preferred embodimentof the present invention as well as various variations thereof. Thoseskilled in the art will recognize that there are numerous othervariations and modifications of this invention that are encompassedwithin the description, the figures and the claims. As required,detailed embodiments of the present invention are disclosed herein;however, it is to be understood that the disclosed embodiments areexamples of the invention, which can be embodied in various forms.Therefore, specific structural and functional details disclosed hereinare not to be interpreted as limiting, but merely as a basis for theclaims and as a representative basis for teaching one skilled in the artto variously employ the present invention in virtually any appropriatelydetailed structure. Further, terms and phrases used herein are notintended to be limiting, but rather to provide an understandabledescription of the invention.

Embodiments of the present invention include a system, device andmethods that control and/or reduce, within a closed or semi-closedenvironment or indoor worker environment, the level or concentration ofone or more substances or contaminants selected from a group consistingof pathogens, allergens and odor-causing agents suspended in orevaporated into the environment's air. Embodiments receive contaminantcontaining air from the closed or semi closed environment, such as theenvironment within a building, room, transportation vehicle cabin,enclosed sports area gymnasium, locker room, living habitat or cleanroom. The contaminant containing air may be pulled or pushed by a blowerthrough a filter that is designed to remove relatively large airborneparticles such as dust, dander, pollen and other particles to helpprotect the interior of embodiments from the buildup of unwantedmaterials on the surfaces of fan motors, heating coils, ultravioletbulbs, or active cell panels, or other surfaces.

The humidity of the filtered contaminant containing air may be sensed byan intake air humidity sensor. The humidity sensor provides a humiditysignal to a controller. When the humidity is below 70 to 100 percenthumidity, the controller signals a humidifier device to add humidity inthe form of water vapor, fine water droplets or steam to the filteredcontaminant containing intake air.

The contaminant containing air and humidity are mixed by a static mixerand permitted to enter into a treatment chamber. In some embodiments,the contaminant containing intake air is preheated prior to mixing withthe humidity. The preheating helps ensure that the water vapor, dropletsor steam mixed with the contaminant containing intake air becomes orremains water vapor in the intake air.

The contaminant containing intake air/vapor mixture (“the air/vapormixture”) is then treated in a treatment chamber wherein contaminantsubstances within the air/vapor mixture are exposed for an effectiveamount of time to ultraviolet light and an oxidizing gas mixturecomprising effective amounts of ozone and hydrogen peroxide. Thecontaminant substances are exposed to the oxidizing gas mixture in thetreatment chamber in order to abate the targeted contaminationsubstance(s).

Embodiment methods create and use mixtures of ozone and hydrogenperoxide vapor within the treatment chamber. The ozone and hydrogenperoxide vapors are each created in the treatment chamber and withinpredetermined ranges by way of (a) a photocatalytic reaction betweenultraviolet (UV) radiation and photocatalytic compounds coating activecell panels, and (b) between the UV radiation, oxygen molecules, and thewater vapor molecules, which are all present within the treatmentchamber.

It has been found that the hydrogen peroxide vapor in the quantity rangerequired in the various embodiments can be generated when the humiditywithin the treatment chamber is between about 75 and 100 percent andwithout humidity saturation or condensation. This process yields anoxidizing gas mixture within the treatment chamber having relativelyhigh concentrations of hydrogen peroxide, and relatively low (but stilleffective) concentrations of ozone. In addition, some of the ozonereacts with the water vapor molecules to produce hydroxyl radicals.Furthermore, some of the hydrogen peroxide and ozone react therebycreating highly oxidative hydroxyl radicals (OH). In addition, variousembodiments also produce super ions in the form of O2 with an extraelectron, which are also very oxidative.

The oxidizing gas mixture created within the treatment chamber haspredetermined concentration ranges of ozone, hydrogen peroxide vapor,hydroxyl radicals, highly oxidative hydroxyl radicals, and super ions.The oxidizing gas mixture can be applied to target contaminants withinthe air/vapor mixture or on an object or surface exposed to theoxidizing gas mixture, for an effective amount of time. Exposure to theoxidizing gas mixture results in complete or partial decontamination,control and/or reduction of most contaminants such as odors, bacteria,viruses, molds, and allergens that are in the air/vapor mixture. Thetreated air/vapor mixture combined with the oxidizing gas mixture(herein after “the treated air/gas mixture”) then exits from thetreatment chamber by way of an output passage into the closed orsemi-closed environment where the oxidizing gas portion of the treatedair/gas mixture can continue to treat air and surfaces within the closedor semi-closed environment until the hydrogen peroxide vapor, ozone,hydroxyl radicals and super ions decompose or become non-oxidizing.

Given that the half-life of ozone vapor is measured in minutes under theconditions employed in the inventive methods and that the half-life ofhydrogen peroxide is very short when in the presence of ozone, thetreated air mixture can still be released and employed in inhabitedclosed or semi closed environments such as rooms or buildings andexhibit concentrations of vaporized hydrogen peroxide below 1.0 ppm,which is below the present OSHA workplace safety limit.

Ozone has a long history of use in purification methods. In June 2001,the U.S. Federal Food and Drug Administration approved ozone for use infood preservation. Currently, ozone is also commonly used to help purifymuch of the tap and bottled water in the US. It is also used to helpkeep fruits and vegetables fresh during storage. Low powered ozonegenerators have been commercially available for many years for in-homeuse. These low powered ozone generator units, however, have proven to beproblematic. More specifically, these prior low powered ozone generatorunits that were considered to be safe for operation in rooms were peoplewere present generated ozone levels at concentrations far too low toeffectively abate mold, pathogens, and allergens from the air in orsurfaces of the room. Conversely, more powerful prior art ozonegeneration units that are considered effective at decontaminating mold,pathogens and allergens frequently generate levels of ozone that wereunsafe for prolonged exposure by animals or people.

The concentrations of ozone created and used in methods and apparatus ofthe present embodiments, however, are considered in an allowableconcentration range for animals and people. Thus, unlike prior methods,during use of embodiments or methods of the invention, animals andpeople do not need to remain outside an area being treated. Moreover,following treatment, ozone levels in the area treated can be quicklyreduced to that of the outside environment where no potentially harmfullevels of residual substances or contaminants are left behind.

Referring now to FIG. 1, a block schematic diagram of an apparatus forenhanced reduction of pathogens, allergens, and odor-causing agents froma closed or semi-closed environment is shown. The environmentcontamination treatment (“ECT”) apparatus 10 may include a variety ofcomponents to help clean and decontaminate environmental air in a closedor semi closed environment such as a room or an inhabitable indoor area.Embodiments of the ECT apparatus 10 may perform particle removal,gaseous pollutant removal, and pollutant destruction to help clean anddecontaminate environmental air of various pollutants includingpathogens, allergens and volatile organic compounds (VOCs). Embodimentsof the ECT apparatus 10 may be incorporated into an HVAC or ventilationsystem of a building, house, room, or indoor area. Portable ECTapparatus 10 embodiments may be configured to be carried from room toroom or to operate within specific areas of a room, but may not beintended for whole house or building pollutant filtration ordecontamination.

Air from the indoor environment becomes intake air 12 as it enters anintake or inlet passage. The intake air 12, also referred to herein ascontaminant containing air or untreated air 12 may be pulled into aninlet passage by a blower device 14. The blower device may becontrollable by a controller 16 to move the inlet air 12 at a variablecubic/feet per min rate depending on a sensed intake humidity ortemperature of the intake air 12. The blower device may be any fan,squirrel cage style blower or other device configured to extract airfrom an indoor environment about outside of the ECT apparatus and movethe extracted air through the intake passage of the ECT apparatus 10.

A particle filter 18 in the form of a mechanical air filter or anelectronic air filter may be positioned before or after the blowerdevice 14. The particle filter 18 is shown in the FIG. 1 as beingpositioned after the intake inlet and before or prior to the blower 14.Mechanical air filters remove particles by capturing them in filtermaterials such as screens, woven or unwoven fabrics, porous paper orfoam, etc. Electronic air cleaners can be in the category ofelectrostatic precipitators, which use a process called electrostaticattraction to trap charged particles. The electrostatic precipitatorsdraw air through an ionization section where particles within the intakeair obtain an electrical charge. The charged particles then accumulateon a series of flat plates called a collector that is oppositelycharged.

In various embodiments, the intake air 12 also passes through a heatersection 20 that heats the intake air to a temperature that will enablewater vapor to be added to the air such that the water vapor will notprecipitate out or become saturated, but instead evaporates into orremains water vapor when mixed with the heated intake air. The heatersection may be controlled by a temperature control signal received fromthe controller 16 or by an electro-mechanical thermostat set to apredetermined temperature.

A humidity sensor 22 and a temperature sensor 24 may also be located inthe inlet passage of the ECT apparatus 10. The intake humidity sensor 22may be a hydrometer located prior to or after the heater section 20. Thetemperature sensor 24 may be positioned after the heater section 20 toprovide feedback in the form of a temperature signal to the controller16 or the thermostat. The intake humidity sensor may provide an intakehumidity signal to the controller 16. The intake humidity signalprovides an indication of the humidity or water content of the intakeair 12. The temperature sensor 24 provides a temperature signalindicative of the temperature of the intake air in the inlet passage or,if a heater section 20 is in the embodiment, the temperature of theheated intake air.

A humidifier device 26 generates water vapor or water droplets that areintended to be added to the intake air. The humidifier device 26 may becontrolled by a humidifier control signal provided by the controller 16.The humidifier device may be any reasonable type of humidifierconfigured to emit water vapor or steam at high enough flow rates tohumidify the intake air flow to a predetermined level of humidity.Embodiments may incorporate an ultrasonic humidifier that produces acool mist using ultrasonic vibrations, an impeller humidifier thatproduces a cool mist using a rotating disk, an evaporator stylehumidifier that uses a fan to blow, for example, intake air through awet wick, filter or belt, or a steam vaporizer that that useselectricity to heat water into steam. The humidifier device 26 createsor is controlled by the controller via a humidifier control signal tocreate enough water vapor to increase the humidity of the intake air tobetween about 75 and 100 percent humidity.

A water source 28 provides water to the humidifier device 26. In variousembodiments the water source 28 is a water container or tank thatrequires refilling by a user. In other embodiments the water source 28may be a connection to a water source associated with the building orroom wherein the ECT apparatus 10 is being used. In order to minimizebuildup of salts, calcium and other mineral deposits in the humidifierdevice 26 or downstream from insertion of water vapor with the intakeair, various embodiments use purified, filtered, reverse osmosis ordistilled water that has a vast majority of the salts, mineral, andother non-H2O molecules removed from the water (“purified water”). Thepurified water may have minimal additives added so as to balance the PHof the water so that it does not attract ions or to be less corrosive toexposed metal surfaces within various embodiments.

In various embodiments, the water vapor output from the humidifierdevice 26 is positioned in the inlet passage of the ECT apparatus sothat the water vapor combines with the intake air in the inlet passageas the inlet air moves through the inlet passage. In other embodiments,there is a defined mixing area 30 within the inlet passage or betweenthe inlet passage and a treatment chamber 32 where the water vapor andthe intake air are mixed so as to create a homogeneous mixture of thecontaminant containing intake air and the water vapor (hereinafter“air/vapor mixture) 33. In some embodiments, the mixing area 30comprises a static mixing structure that mixes or swirls the intake airand the water vapor as they move through the static mixing structure,which may comprise vents, static blades, helical structures, or otherturbulence creating structures. In some embodiments, the heating deviceand the static mixer may be combined to both heat and mix the air/vapormixture.

The air/vapor mixture that exits the mixing area 30 may pass anair/vapor mixture humidity sensor 34. This humidity sensor 34 senseswhether the humidity of the air/vapor mixture is within a desired rangeor setting that is between 75 and 100 percent humidity. Here thehumidity sensor 34, measures the amount of moisture in the air/vapormixture. The humidity sensor 34 can be any type of hygrometer thatprovides a feedback humidity signal to the controller 16 indicative ofthe percent humidity in the air/vapor mixture. The controller 16 may usethe feedback humidity signal to determine whether the water vapor outputof the humidity device requires adjustment. Alternatively, the humiditysensor 34 may be a portion of a humidistat that controls the output ofthe humidifier more directly in order to maintain the humidity of theair/vapor mixture within the prescribed range of 75 to 100 percent,which is often much higher than the normal humidity percentage ofbetween about 30 and 70 percent humidity found in buildings or roomswhere people work.

In various embodiments, the controller 16 receives a temperature signalfrom the temperature sensor 24. The temperature signal provides thetemperature of the intake air prior to being mixed with the water vapor.The controller 16 also may receive one or more humidity signals. One ofthe humidity signals, for example from humidity sensor 22, may providean indication of the specific humidity of the intake air. The otherhumidity signal may provide a signal or indication of the specifichumidity of the air/vapor mixture. “Specific humidity” is defined as theratio of the water vapor content of the air/vapor mixture to the totalair content on a mass basis. The controller 16, is configured to use theair temperature signal and the humidity signal(s) to determine how muchwater vapor or the rate at which water vapor needs to be produced by thehumidifier and mixed with the intake air 22 to provide an air/vapormixture that has a humidity within a predetermined humidity percentagerange of between 75 and 100 percent humidity.

In some embodiments, the controller 16 is configured to determine therelative humidity of the intake air that enters the inlet passage and/orthe intake air after it is heated by the heater section 20, depending onwhether the embodiment includes a heater section 20. “Relative humidity”is defined as the amount of moisture in the air (determined via moisturemass or vapor pressure) divided by the maximum amount of moisture thatcan exist in the air at the specific temperature (determined via maxmoisture mass or saturation vapor pressure). Determining the relativehumidity may be done in various embodiments when the temperature of theintake air is not warm enough, when mixed with the water vapor, toachieve a predetermined specific humidity without the water vaporbecoming saturated in the intake air 12 and resulting in condensation ofthe water vapor within the mixer 30 or the treatment chamber 32.

In some embodiments, the relative humidity of the intake air (heated orunheated) is determined by the controller 16 by using the temperaturesensor signal and the humidity signal. Relative humidity can beexpressed as the ratio of the vapor partial pressure of the intake airto the saturation vapor partial pressure of the intake air at the actualtemperature of the intake air. The following equations may be used bythe controller to determine an amount of water vapor that needs to beadded to the intake air in order to achieve a relative humidity of 75 toabout 100%:

φ=p _(w) /p _(ws)100%  (1)

where

φ=relative humidity (%)

p_(w)=water vapor partial pressure (mbar)

p_(ws)=saturation water vapor partial pressure at the actual temperatureof the air (mbar).

The maximum saturation pressure of water vapor in moist air varies withthe temperature of the air vapor mixture and can be expressed as:

p _(ws) =e ^((77.3450+0.0057T−7235/T)) /T ^(8.2)  (2)

where

p_(ws)=water vapor saturation pressure (Pa)

e=the constant 2.718 . . .

T=temperature of the moist air (K)

Alternatively, the water vapor saturation pressure can be stored as asaturation pressure data lookup table in a memory device memory 17 or aspart of the controller 16. Table 1 provides data that can be used inembodiments to determine the water vapor saturation pressure atdifferent temperatures.

TABLE 1 Temperature Saturation Vapor Pressure (p_(ws)) (° C.) (° F.)(mbar, millibar, mb) −18 0 1.5 −15 5 1.9 −12 10 2.4 −9 15 3.0 −7 20 3.7−4 25 4.6 −1 30 5.6 2 35 6.9 4 40 8.4 7 45 10.3 10 50 12.3 13 55 14.8 1660 17.7 18 65 21.0 21 70 25.0 24 75 29.6 27 80 35.0 29 85 41.0 32 9048.1 35 95 56.2 38 100 65.6 41 105 76.2 43 110 87.8 46 115 101.4 49 120116.8 52 125 134.2 1 bar = 1000 mbar = 10⁵ Pa (N/m²) = 0.1 N/mm² =10,197 kp/m² = 10.20 m H₂O = 0.9869 atm = 14.50 psi (lb_(f)/in²) = 10⁶dyn/cm² = 750 mmHg

The water vapor partial pressure, p_(w), is the pressure at which watervapor is in thermodynamic equilibrium with its condensed state. Athigher pressures, water would condense out of the air. The water vaporpressure is the partial pressure of water vapor in any gas mixture inequilibrium with solid or liquid water. Table 2 provides the neededwater vapor pressure (p_(w)) data for temperatures ranging from thefreezing point to the boiling point of water. The vapor pressure data(p_(w)) can also be stored in the memory 17 for use by the controller.

TABLE 2 Temperature Pressure (degrees C.) (mmHg) 0 4.6 1 4.9 2 5.3 3 5.74 6.1 5 6.5 6 7 7 7.5 8 8 9 8.6 10 9.2 11 9.8 12 10.5 13 11.2 14 12 1512.8 16 13.6 17 14.5 18 15.5 19 16.5 20 17.5 21 18.7 22 19.8 23 21.1 2422.4 25 23.8 26 25.2 27 26.7 28 28.3 29 30 30 31.8 31 33.7 32 35.7 3337.7 34 39.9 35 42.2 36 44.6 37 47.1 38 49.7 39 52.4 40 55.3 41 58.3 4261.5 43 64.8 44 68.3 45 71.9 46 75.7 47 79.6 48 83.7 49 88 50 92.5 5197.2 52 102.1 53 107.2 54 112.5 55 118 56 123.8 57 129.8 58 136.1 59142.6 60 149.4 61 156.4 62 163.8 63 171.4 64 179.3 65 187.5 66 196.1 67205 68 214.2 69 223.7 70 233.7 71 243.9 72 254.6 73 265.7 74 277.2 75289.1 76 301.4 77 314.1 78 327.3 79 341 80 355.1 81 369.7 82 384.9 83400.6 84 416.8 85 433.6 86 450.9 87 468.7 88 487.1 89 506.1 90 525.8 91546 92 567 93 588.6 94 610.9 95 633.9 96 657.6 97 682.1 98 707.3 99733.2 100 760

Thus, in some embodiments the relative humidity of the intake air 12 orthe air/vapor mixture can be determined by the controller by sensing thetemperature and humidity of the intake air and/or the air vapor mixturerespectively. The controller can use the calculated relative humiditysensed in order to signal the humidifier device.

In various embodiments the controller 16 can adjust the blower device 14blower speed, the power that the heater section 20 operates at to heatthe intake air flow, and/or the rate at which the humidifier outputswater vapor in order to maximize the specific or relative humidity ofthe air/vapor mixture without saturating the water vapor such that itcondenses on the inside surfaces of the ECT apparatus 10. In variousembodiments, either the specific humidity or the relative humidity ofthe air/vapor mixture is set to be maintained at a predetermined settingthat is between about 75 to 100 percent. In other words, the controller16 in conjunction with the temperature and humidity sensors isconfigured and/or electrically connected to control one or more of theblower device, the heater device, and the humidifier such that thespecific or relative humidity of the resulting air/vapor mixture iswithin a predetermined range or held at a predetermined setting.

The air/vapor mixture proceeds to enter the treatment chamber 32. Thetreatment chamber 32 has within it a relatively open chamber or areathat allows the air/vapor mixture to slow down in movement velocity ascompared with the movement through the inlet passage. The treatmentchamber 32 may be an area within the housing of the apparatus 10 or aspecified chamber area. The treatment chamber 32 is configured to carryout a photocatalytic oxidation process on the air/vapor mixture. Withinthe treatment chamber there is a plurality of photocatalytic surfaces36. The photocatalytic surfaces 36 may be on the interior walls of thereaction chamber and/or be part of one or more active panels 38. Thephotocatalytic surfaces 36 can be uniformly or selectively coated ortreated with one or more photocatalytic materials, such as titaniumdioxide or other known photocatalytic compounds.

Also within the treatment chamber 32 is a UV light source 40 configuredto emit UV light within a predetermined frequency range. The UV light orradiation emitted from the UV light source 40 is directed to impinge onthe photocatalytic surfaces 36, which in turn are energized by the UVlight and operate by performing a photocatalytic oxidation process thataides in the purification of the air/vapor mixture within the treatmentchamber 32 by converting allergens and toxic compounds, and othercontaminants via oxidation, to benign constituents. In variousembodiments, the photocatalytic surfaces 36 may be coated with asuitable sol-gel or hydrophilic photocatalytic coating having nano ornon-nano titanium dioxide along with several transition elements addedto the coating in order to enhance or help optimize the overallcatalytic effect.

In various embodiments, UV radiation reflective surfaces 44 are alsoincorporated into the treatment chamber 32 in order to help reflect UVradiation 42 emitted from the UV source 40 and direct it toward thephotocatalytic surface 36 of one or more active panels 38 or otherphotocatalytic coated surfaces within the treatment chamber 32. The UVreflective surfaces 44 help to enhance or maximize the photocatalyticoxidation process within the treatment chamber 32 by directing stray orreflected UV radiation back toward a photocatalytic surface. Thereflective surfaces 44 may be configured to reflect UV radiation bybeing buffed, coated with a reflective material, or made of a material,such as aluminum, stainless steel, or certain types of plastics/polymersor other materials that are configured to reflect UV radiation or light.

The combination of the UV radiation 42 impinging through the air/vapormixture and on the photocatalytic surfaces 36 produces oxidativemolecules that include ozone, hydrogen peroxide, hydroxyl radicals, andsuper ions. The combination of these oxidative molecules treat theair/water vapor thereby oxidizing a significant portion of thecontaminants contained therein rendering them benign.

It has been determined that setting the humidity or relative humidity ofthe air/vapor mixture between about 75% and 100% humidity (or relativehumidity) significantly aides in increasing the efficiency of thecreation of ozone and hydrogen peroxide from the reaction of ultravioletradiation with the photocatalytic surfaces and the air and further withthe reaction of ozone with water vapor in order to generate hydrogenperoxide.

It is unclear at this time to the inventors exactly how the water vaporhelps increase the efficiency of these reactions, that it is partiallyunclear to the inventors whether having additional water molecules(i.e., high humidity) within the treatment chamber 32 helps and/orwhether the water molecules further catalyze the overall reaction byacting as some type of lens, electron donor, or amplifier of the UVradiation on individual molecules within the air/vapor mixture toenhance the reaction process.

Regardless, the inventors determined that within the treatment chamberwhen the humidity is between 75% and 100%, an ozone level can bemaintained between 0.001 ppm and about 0.007 ppm. Furthermore, ahydrogen peroxide (H2O2) level between 0.25 ppm and 0.45 ppm can also bemaintained. Additionally, a significant number of hydroxyl radicals andsuper ions (O2 with an extra electron) are also created. The ozone,hydrogen peroxide, hydroxyl radicals and super ions are all maintainedwithin the treatment chamber at levels capable of oxidizing variouscontaminants within the air/vapor mixture rendering them benign. Thehydroxyl radial production, although small, appears to be heavilyrelated to the percentage of humidity present. Additionally, it has beendetermined that the closer the humidity or relative humidity is to 100%the easier it is to maintain the hydrogen peroxide level closer to 0.45ppm and the greater amount of hydroxyl radicals and super ions present.

The treated air/vapor mixture is then exhausted or output from thetreatment chamber 32. In various embodiments, a blower may be used tohelp move the treated air/vapor mixture out of the treatment chamber andout of the environmental containment treatment apparatus 10.

In some embodiments, the treated air/vapor mixture is exhausted oroutput back into the environment from which the intake air 12 wasextracted. The treated air/vapor mixture will continue to have oxidativeand contaminant cleaning properties for a period of time after beingexhausted from the apparatus 10. As such, the exhausted treatedair/vapor mixture will comprise air, benign contaminants, residualcontaminants, ozone at a level between 0.001 ppm and about 0.007 ppm,hydrogen peroxide at a level between about 0.005 ppm and 0.45 ppm, 75 to100% humidity, hydroxyl radicals, and super ions. The treated air/vapormixture exhausted from the apparatus in this embodiment furtherneutralizes various contaminants from the atmosphere outside of theapparatus 10 and in various configurations naturalizes variouscontaminants on surfaces of which the treated air/vapor mixture comes incontact.

In various embodiments, the concentration of ozone in the treatedair/vapor mixture that is exhausted, is generally greater or equal to 0ppm, but less than between 0.0060 ppm and 0.0070 ppm. When the ozonelevel drops just below about 0.0070 ppm, the exhaust or output from thetreatment chamber is less irritating to people or animals in theenvironment outside the apparatus 10, yet still effective atneutralizing contaminants.

Hydroxyl radicals are significantly more oxidative than ozone moleculesper ppm. Hydroxyl radicals are produced in a reaction within thetreatment chamber 32 between ozone and water molecules.

The amount of hydroxyl radicals formed in the treated air/vapor mixturefrom ozone and humidified air, may be relatively small compared to theamount of hydrogen peroxide formed therein. The amount of hydroxylradicals formed is highly dependent on the amount of humidity present inthe treatment chamber. The closer the humidity (or relative humidity) isto 100%, the greater the creation of hydroxyl radials. Additionally, thegreater the ratio of hydrogen peroxide created relative to the amount ofair/vapor mixture introduced into the treatment chamber, in which thereaction occurs, results in increasing or maximizing the number ofhydroxyl radicals formed therein. Furthermore, some of the hydrogenperoxide created in the treatment chamber will react with the createdozone, thereby converting the ozone and hydrogen peroxide molecules tomore highly oxidative hydroxyl radicals (OH).

The resultant treated air/vapor mixture provides at least three methodsof neutralizing the targeted contaminants (i.e., the targeted pathogens,allergens and/or odor-causing agents (VoCs)). The first method ofneutralizing the targeted contaminants is by direct oxidation of acontaminant by the ozone; the second method of neutralizing the targetedcontaminants is by oxidation via the hydrogen peroxide; the third is byoxidation by hydrogen radicals; and a fourth oxidation is by super ions.Additionally, contaminants are neutralized directly by the UV radiationemitted by the UV radiation source.

According to various embodiments, the concentration of hydrogen peroxidecreated within the treatment chamber 32 is between about 0.25 ppm and0.45 ppm. The higher the concentration of hydrogen peroxide the greaterthe ability for the contaminants to be oxidized and rendered benignwithin the air/vapor mixture or when the treated air/vapor mixture isexhausted or output into the environment about the ECT apparatus 10.

It has been found that decontamination of the contaminants in theair/vapor mixture is greatest when the ratio of hydroxyl radicals toozone is maintained as high as possible. Thus, embodiments areconfigured to create or provide a ratio of hydrogen peroxide to ozonethat is between about 3:1 and 4:1. That is by providing or creating aratio of hydrogen peroxide to ozone within the range of 3:1 and 4:1 thatwill also maximize the ratio of hydroxyl radicals to ozone createdwithin the treatment chamber due to the reaction of hydrogen peroxideand ozone. Thus, the importance of the high humidity is evident so as tomaximize hydrogen peroxide production relative to ozone.

The methods of the present invention can be used to control or reducethe level of a wide variety of pathogens, allergens and/or odor-causingagents that are in the surrounding air environment and pulled into theintake of the ECT apparatus 10 and then treated with the variousoxidizing molecules created within the treatment chamber 32 or when thetreated air/vapor mixture (which initially includes the prescribedamounts or ratios of ozone, hydrogen peroxide, hydroxyl radicals andsuper ions) is exhausted or output back into the surrounding airenvironment. The treatment chamber atmosphere as well as the treatedair/vapor mixture exhausted from the ECT apparatus 10 both activelyoxidize and neutralize contaminants by coming into contact with thetargeted pathogen(s), allergen(s) and/or odor-causing agents to controlor reduce the level thereof.

Various variations of the embodiments may be used to control or reducethe level of pathogens, allergens and/or odor-causing agents in adefined space, such as a room, house, locker room, manufacturing area,building, cargo bay, medical procedure room, laboratory, transportationvehicle, warehouse/storage area or the like, simply by introducing anECT apparatus 10 or the exhausted treatment air/vapor mixture into theenvironment being treated.

Various embodiments can be configured to control or reduce the level ofcontaminants, including most pathogens, allergens and/or odor-causingagents, on one or more surfaces of an object by directing a stream ofoutput or exhaust treated air/vapor mixture toward and/or onto theobject surfaces. Moreover, in the case of an object that is smaller thanor can fit within the interior of the treatment chamber 32, such anobject can be placed and treated inside the treatment chamber.Alternatively, if an object is too large to be placed within anembodiment's treatment chamber, then the object can be placed in anenclosed space within a box or sealed chamber, wherein the treatedair/vapor mixture from the treatment chamber 32 is introduced.

Embodiments can further be used to reduce the level of the substancesdiscussed herein, including various pathogens, allergens, and VolatileOrganic Compounds (VOCs) (i.e., odor causing agents).

Pathogens that can be controlled, neutralized, killed or made benign bythe various embodiments include, but are not limited to, the following:Bacillus anthracis (anthrax); Clostridium botulinum (botulism); Brucellaspecies (brucellosis); Burkholderia mallei (glanders); Burkholderiapseudomallei (melioidosis); Chlamydia psittaci (psittacosis); Coxiellabumetii (Q fever); Cryptosporidium parvum; E. coli strains, includingO157:H7; emerging infectious diseases, such as Nipah virus andhantavirus; Norwalk virus; Severe Acute Respiratory Syndrome (SARS);Acquired Immune Deficiency Syndrome (AIDS) virus; Human ImmunodeficiencyVirus (HIV); Francisella tularensis (tularemia); Rickettsia prowazekii(typhus fever); Salmonella species (salmonellosis); Salmonella Typhi(typhoid fever); Shigella (shigellosis); Staphylococcal enterotoxin B;Variola major (smallpox); Vibrio cholerae (cholera); Viral encephalitis(including Venezuelan equine encephalitis, eastern equine encephalitis,western equine encephalitis); Viral hemorrhagic fevers (filoviruses[e.g., Ebola, Marburg] and arenaviruses [e.g., Lassa, Machupo]); andYersinia pestis (plague).

Other pathogens that can be controlled, neutralized, killed or madebenign include molds, such as Acremonium; Alternaria; Aspergillusfumigatus; Aspergillus niger; Aspergillus species Var. 1; Aspergillusspecies Var. 2; Aureobasidium; Bipolaris, Chaetomium; Cladosporium,Curvularia; Epicoccum; Fusarium; Geotrichum; Memnoniella; Mucor; Myceliasterilia; Nigrospora; Paecilomyces; Penicillium species Var. 1;Penicillium species Var. 2; Pithomyces; Rhizopus; Sporothrix;Sporotrichum; Stachybotrys; Syncephalastrum; Trichoderma; and Yeast.

Indoor allergens that can be remediated or neutralized by an apparatusor method embodiment include dust mite feces, dander, rodent urine andcockroach allergens.

Dust mite feces are the major source of allergic reaction to householddust. The mites thrive on shed human skin and are most commonly found inbedrooms, where skin cells are abundant. Preventive measures includefrequently laundering bed linens in hot water and removing carpets fromthe room. In some extreme cases, homeowners have even been forced toencase the bed mattress, box springs, and pillows in vinyl covers.Additionally, embodiments described herein can also help to remediateand neutralize dust mite feces as an allergen by oxidizing andneutralizing its allergic effect on humans.

Other allergens of animal origin include skin scales shed from humansand animals, otherwise known as dander. Dander from such animals ascats, dogs, horses, and cows can infest a home even if the animal hasnever been inside.

Rodent urine from mice, rats, and guinea pigs are another group ofallergens.

Cockroach-derived allergens come from the insect's discarded skinswhich, as they disintegrate over time, become airborne and inhaled.

In addition, tobacco smoke, engine exhaust, cooked or rotten food odorsand similar odor-causing agents can also be remediated, reduced orcontrolled by various embodiments of the ECT apparatus and methodsdescribed herein.

It has also been found that odor-causing agents, such as volatileorganic compounds (VOCs) from sources such as household productsincluding paints, carpets, paint strippers, and other solvents; woodpreservatives; aerosol sprays; cleansers and disinfectants; mothrepellents and air fresheners; stored fuels and automotive products;hobby supplies; dry-cleaned clothing, and the like can be remediated,reduced or controlled by various embodiments and methods. VOCs includeorganic solvents, certain paint additives, aerosol spray canpropellants, fuels (such as gasoline, and kerosene), petroleumdistillates, dry cleaning products, and many other industrial andconsumer products ranging from office supplies to building materials.VOCs are also naturally emitted by a number of plants and trees.

Some of the more common VOCs include ammonia, ethyl acetate, methylpropyl ketone, acetic acid, ethyl alcohol, methylene chloride, acetone,ethyl chloride, n-propyl chloride, acetylene, ethyl cyanide,nitroethane, amyl alcohol, ethyl formate, nitromethane, benzene, ethylpropionate, pentylamine, butane, ethylene, pentylene, butyl alcohol,ethylene oxide, propane, butyl formate, formaldehyde, propionaldehyde,butylamine, formic acid, propyl alcohol, butylene, heptane, isopropylchloride, carbon tetrachloride, hexane, propyl cyanide, chlorobenzene,isobutane, propyl formate, carbon monoxide, hexyl alcohol, propylamine,chlorocyclohexane, hydrogen gas, propylene, chloroform, hydrogensulfide, tertiary butyl alcohol, cyclohexane, isopropyl acetate,tetrachloroethylene, cylohexene, methane, toluene, 1-dichloroethane,methyl alcohol, 1,1,2-trichloroethane, 1,2-dichloroethane, methylchloride, trichlorethylene, diethyl ketone, methyl chloroform,triethylamine, diethylamine, methyl cyanide, xylene, ethane, and methylethyl ketone.

Other odor-causing agents that can be reduced or controlled by variousembodiments of the invention include skunk odors, urine, pet odors,flatulence, body odors, food odors, mold and mildew odors, decomposingmaterial odors and the like.

Embodiments may be designed with alternate configurations in order tobetter subject the particular contaminant(s) that are to be controlledor reduced to the treated air/vapor mixture under conditions that aresufficient to provide an effective oxidative concentration of ozone andhydrogen peroxide. The time duration of a treatment can then be set oradjusted as necessary to ensure satisfactory kill and/or neutralizationlevels of the contaminants.

As noted above, any interior or contained space within or proximate tothe treatment chamber is amenable to treatment by methods of variousembodiments of the invention. For example an interior portion or theentire inside of a single family home, apartment building, officebuilding, school, hospital, doctor's office, laboratory, restaurant,ship or boat, train, bus, airplane, truck, cargo area, locker room,bathroom, shower room, kitchen or butcher area and the like are allwell-suited to treatment by an ECT apparatus.

Various embodiments of the invention can also be employed to reduce orcontrol contaminants that are on the surfaces of an article ofmanufacture. Articles of manufacture that can be treated includematerials that can tolerate exposure to effective concentrations ofozone and hydrogen peroxide at the humidity and temperature conditionsassociated with the embodiment employed without the article ofmanufacture suffering unacceptable damage. Examples of some articles ofmanufacture that can be treated may include, clothing and garments,shoes, bedding, linens, and rugs; mail, documents, paper products;furniture; food items, agricultural products such as seed, grains, cutflowers, produce, fruits vegetables, and live plants, articles made ofplastics, polymers, metal, wood, glass, acrylic, stone, and packagingmaterials; and the like.

FIG. 2 depicts another embodiment of an Environmental ContaminationTreatment (ECT) apparatus that may include a door or airlock 102 toallow articles of manufacture to be treated by being placed inside thetreatment chamber 104 that is suitably constructed to maintain thedesired concentrations of ozone, hydrogen peroxide, hydroxyl radicals,super ions, humidity and temperature. The articles to be treated areplaced inside the treatment chamber 104, via the airlock 102 and on adecontamination platform 106. In some embodiments, the article ofmanufacture 108 may be suspended within the chamber (not specificallyshow) so that a maximum amount of the article's surface area can besubjected to the treated air/vapor mixture 110 within the treatmentchamber 100.

In another embodiment an automated decontamination treatment process maybe performed as articles to be treated are moved, for example via amoving platform or conveyor 106, through an airlock or opening 102 andinto the treatment chamber 104 for treatment by the treated air/vapormixture 110 for a suitable time period and then moved out of the chamberthrough the outlet passage. Such automated processes can be particularlywell suited for decontamination of multiple articles in a serial mannersuch as multiple medical instruments or the decontamination of animalcarcasses or meat products (e.g., beef, pork, poultry, seafood, and thelike) for pathogens such as salmonella and E. coli. The conveyer 106 maybe configured such that the treated air/vapor mixture 110 can contactthe underside of the article of manufacture 108 thereon.

In various embodiments, the temperature of the water vapor may begreatly increased. A heating element 114 can be included in thetreatment chamber 104 such that articles of manufacture aredecontaminated, disinfected and sterilized more quickly than commonsteam sterilization techniques at or around the same temperature. Insuch embodiments, the steam and temperature of the air/vapor mixture ismaintained between about 121° C. (250° F.) and about 132° C. (270° F.).

Still referring to FIG. 2, intake air 116 enters an inlet 118 of the ECTapparatus 100. A blower 120 forces the intake air 116 through anoptional heater section 122 and toward the treatment chamber 104. Theheater section 122 heats the intake air to a temperature high enoughsuch that when water vapor 122 is added to the intake air 116, theresulting air/vapor mixture 126 will not be saturated with water and/orthe water molecules will not condense within the treatment chamber 104.

Water vapor 124 in the form of steam or atomized water mist is producedby the humidifier device 128. The humidifier device 128 may beconfigured to emit water vapor, micro water droplets or steam at highenough rates to humidify the intake air flow 116 to a predeterminedlevel of humidity. The humidifier device 128 may be an ultrasonichumidifier, an impeller humidifier, an evaporator style humidifier, orsteam vaporizer or other reasonable humidifier device. The rate ofhumidification may be controlled by a controller, a humidistat manually(not specifically shown). A water source 130 provides water to thehumidifier device 128. In various embodiments the water source 130 mayinclude water purification system in order to provide purified ordistilled water to the humidifier device 128 so as to alleviate thebuildup of mineral scale within the ECT apparatus 100. The intake air116 when combined with the water vapor 124 is referred to herein as theair/vapor mixture 126.

The air/vapor mixture 126 proceeds toward the treatment chamber 104 andis mixed or stirred by a static mixer 132 along the way. The staticmixer helps water droplets evaporate into water vapor as well as helpuniformly mix the water vapor with the intake air so as to be ahomogenous air/vapor mixture 126 as it enters the treatment chamber 104.

Within the treatment chamber 104 there is at least one ultraviolet (UV)radiation source 134 positioned such that UV radiation 136 produced bythe UV radiation source 134 impinges on the surface or surfaces of oneor more active panels or active cell panels 138. The UV radiation source134 may comprise one or more UV light emitting light bulbs or LEDs. IfUV radiation emitting LEDs are used, there may be panels with one ormore arrays LEDs positioned thereon.

In FIG. 2, a cross-section of 3 different active cell panels 138 a, 138b and 138 c embodiments are depicted and referred to generally as 138.In general, the active cell panels 138 include a plurality of surfaces.The active cell panels 138 also comprise a plurality of pass throughstructures or apertures 140 extending from a first side to a second sideof each active cell panel 138. The surfaces of the active cell panels138, including the surfaces of the apertures 140 are uniformly orselectively coated or treated with one or more photocatalytic materials,such as titanium dioxide and other similarly performing photocatalyticor photocatalytic process aiding substances or compounds.

The photocatalytic coated surfaces of the active cell panels 138 areenergized upon direct and reflected impingement of UV radiation or lightemitted from the UV radiation source 134. In various embodiments, thephotocatalytic materials may be a compound comprising a hydrophilicphotocatalytic material having nano or non-nano titanium dioxide andseveral transition elements added thereto in order to enhance or helpoptimize the overall photocatalytic effect when in the presence ofultraviolet radiation 136 and the air/vapor mixture 126.

The apertures 140 extending from one side to another side of the activecell panels 138 provide 2 advantageous functions. First the aperturesprovide additional photocatalytic coated surface area for the UVradiation 136 to impinge upon and second the apertures enable theair/vapor mixture 126 to be treated within the treatment chamber 104 bypassing through one or more apertures as the air/vapor mixture movesthrough the treatment chamber thereby adding turbulence to the flow andenhancing the catalytic oxidation process of the active cell coatingwith the UV radiation and the air/vapor mixture in order to produceozone, hydrogen peroxide, hydroxyl radicals, and super ions.

Although this will be explained in more detail below, the differencebetween the active cell panels 138 a, 138 b, and 138 c has to do withthe angle at which the apertures 140 extend through each of the activecell panels 138. For example, in the active cell panel 138 a theapertures 140 extend through the active cell panel perpendicular to afirst and second surface of the active cell panel 138 a. Alternatively,the active cell panel 138 b has apertures 140 that extend parallel toeach other and at an angle with respect to the first and second side ofthe active cell panel 138 b. Additionally, the active cell panel 138 chas apertures 140 that extend from a first side to a second side of theactive cell panel 138 c and angles that may be different for some of theapertures with respect to other ones of the apertures.

It was found through experimentation that unexpectedly, the angledapertures of active cell panels 138 b and 138 c produced more efficientphotocatalytic reaction perhaps at least in part due to increased directimpingement of the UV radiation 136 onto the photocatalytic coatedsurfaces (rather than reflected UV radiation), which ultimately reducedor eliminated certain pathogens, allergens and odor causing agentsbetween 2 and 8 times faster than the perpendicular apertures of activecell panel 138 a.

In this embodiment of the treatment chamber 104, the active cell panelsare generally in line or parallel with the overall general flow ofair/vapor mixture 126 and treated air/vapor mixture 110. It isunderstood that in other embodiments, the length of the active cellpanels maybe directed to be perpendicular to or angled with respect tothe general overall flow of the treated or untreated air/vapor mixturesthereof thereby providing additional mixing, turbulence and agitation tothe air/vapor mixture flow across the photocatalytic surfaces andincreasing the production of ozone and hydrogen peroxide so as to alsomaximize the rate of the oxidative reactions with contaminants withinthe air/vapor mixture 126.

Additionally, within the treatment chamber 104 there may be additionalstatic mixer elements 142 to provide additional flow agitation to theair/vapor mixture 126 as it is converted via interaction with the UVradiation and the photocatalytic interaction with the active cell panels138 into the treated air/vapor mixture 110. The treated air/vapormixture 110 comprises air, ozone in a concentration of from 0.001 ppm toabout 0.007 ppm, hydrogen peroxide in a concentration between about 0.25ppm and about 0.45 ppm, humidity of between about 75% and 100%, hydroxylradicals, super ions (O₂ with an extra electron), benign contaminants,and some contaminant ruminants that have not been oxidized.

If an article of manufacture 108 is positioned within the treatmentchamber 104 on, for example, the decontamination platform or conveyor106, then the treated air/vapor mixture 110 can be used to control orreduce the amount of contamination (in some cases completelydecontaminate) contaminants on the surfaces of the article ofmanufacture 108. Then after interacting with the contaminants on thesurfaces of the article of manufacture 108, the treated air/vapormixture 110 exits the treatment chamber 104 via the outlet passage 112.

The treated air/vapor mixture 110 that exits treatment chamber 104 byway of the outlet passage 112 may be directed into the room orenvironment so as to further reduce or control the level of pathogens,allergens and/or odor-causing agents in the air or on surfaces ofobjects within the environment.

In other embodiments, an ECT apparatus may be used to periodicallydestroy, kill, oxidize or render benign contaminants within anenvironment that is a closed or partially closed environment such as aroom or other area including, but not limited to a surgical suite in ahospital, a treatment or waiting room in a clinic, a kitchen or arestaurant, a meat processing area of a meat processing plant or thelike. In such embodiments, it is generally preferred to permanentlyinstall equipment in a location adjacent to the area to be treated.

In general, photocatalytic oxidation (PCO) is achieved when ultravioletradiation impinges on the titanium oxide-based coating of the activecell panels 138. This process creates hydroxyl radicals and super-oxideions, which are highly reactive electrons. These highly reactiveelectrons aggressively combine with contaminants in the air, such aspathogens, allergens and VOCs. Once bound together, a chemical reactiontakes place between the super-charged ions and the contaminant,effectively oxidizing or burning the contaminant. This process breaksdown the contaminant into harmless carbon dioxide and water molecules(and some other molecules) making the resulting treated air morepurified. Additionally, photocatalytic oxidation is produced when theair/vapor mixture is exposed to UV radiation (or photons) that passedthrough a catalyst comprising specific nano-sized mineral compounds suchas titanium oxide. After the catalyst is exposed by the UV radiation,three specific free radicals are created and released, which destroycontaminants as discussed herein. During the process, hydrogen peroxide,hydroxyl radicals, and hydroxides attach themselves to specificorganisms and kill them.

In alternative embodiments other suitable techniques for generatingozone such as electrical discharge ozone generators (not specificallyshown) may also be incorporated into the treatment chamber 104. Anysuitable method or apparatus, or combination thereof, can be used togenerate ozone and hydrogen peroxide for use in the inventive methods aslong as the recommended concentrations are maintained.

Although there are commercially available devices that generate ozoneand hydrogen peroxide by either ultraviolet or corona discharge, thesecommercially available devices must be significantly modified in orderto operate in an environment having very high humidity and/or are ableto produce the necessary amounts of hydrogen peroxide produced in thevarious embodiments of the invention. Illustrative examples of knownozone and hydrogen peroxide producing devices include, but are notlimited to, the devices disclosed in U.S. Pat. No. 6,955,751; U.S.Patent Publication No. 2007/0245938; and U.S. Patent Publication No.2009/041617. That is, even though these prior art devices generatehydrogen peroxide through the reaction of ozone and water vapor, thelevel of water vapor (i.e. relative humidity) made available therein isinsufficient to achieve the results of the various embodiments describedherein.

According to the methods of the present invention, the humidity (or insome embodiments that do not include an intake air heating device, therelative humidity) of the air/vapor mixture in which hydrogen peroxideis generated must be at least about 70%. It has been found that theefficiency of producing the needed 0.25 ppm to 0.45 ppm hydrogenperoxide is greatly increased when the humidity is as high as possiblemeaning between 75% and 99% and/or as close to 99% humidity as possiblewithout water vapor condensation within the ECT apparatus.

Referring now to FIG. 3, another example of an ECT apparatus 200 isshown. Intake air 202 is drawn into an inlet passage 204 of the ECTapparatus 200 by a blower device 206. Some embodiments may also includea heating device 208 that heats the intake air to a temperature suchthat water vapor 214 added to the intake air 202 will remain a vaporwhen mixed and combined as an air/vapor mixture 210. A static mixer 212may be placed within the inlet passage 204 so as to mix the water vapor214 with the intake air 202 upon entry into the treatment chamber 216.

The water vapor 214 may be provided as fine droplets, a mist, steam oras evaporated water vapor from a humidifier device 218. The humidifierdevice 218 receives water from a water source 220. The water receivedmay be purified or distilled water so as to minimize calcium, salt orother mineral deposit buildup over time with in the various embodiments.

The air/vapor mixture 210 enters the treatment chamber 216. Across-sectional area of the treatment chamber 216 that is perpendicularto the general air/vapor mixture flow is between two and 30 timesgreater than a cross-sectional area perpendicular to the general intakeair flow of the inlet passage 204. As such, the flow rate of theair/vapor mixture 210 is significantly slower in the treatment chamberthan the intake air flow in the inlet passage. The slower flow ratehelps increase or maximize the treatment process of the air/vapormixture 210 as well as the contaminants.

Within the treatment chamber 216 of some embodiments is a removablemodular insert 220. The removable modular insert 220 simplifiesmaintenance and repair of the embodiment by making it convenient andless labor intensive to change or clean the active cell panel or UVradiation sources as well as gain access to the interior of thetreatment chamber. The removable modular insert has sockets or positions222 wherein active cell panels 224 may also be removably attached. Inthe embodiment shown in FIG. 3, the active cell panels 224 areeffectively positioned such that their length L is generallyperpendicular to the flow of the air/vapor mixture 210 as it movesthrough the interior of the treatment chamber 216. The active cell panel224 comprises an array of cell apertures 226 that extend transverselyfrom a first side to a second side through the active cell panel 224.The cell apertures 226 and positioning of the active cell panels 224allow the air/vapor mixture 210 to flow through the cell apertures andover the many cell aperture surfaces as it is treated within thetreatment chamber 216.

The active cell panels 224, including the surfaces of the apertures 226(which extend transversely through each active cell panel) are uniformlyor selectively coated or treated with one or more photocatalyticmaterials, such as titanium dioxide and/or similar compounds alsodiscussed herein. The photocatalytic materials, also referred to asphoto catalytic oxidative materials, are energized upon receipt ofultraviolet (UV) radiation and thereby operate to support aphotocatalytic oxidation process that aides in the purification of theair/vapor mixture 210 within the treatment chamber 216.

The removable modular insert 220 may be configured in a variety of wayssuch as, for example, it can be inserted into and/or removably attachedto an exterior wall of the treatment chamber 216 such that the pluralityof active cell panels 224 are positioned within the interior of thetreatment chamber 216. In some embodiments, the modular insert may alsoinclude or be limited to only having electrical sockets or connectors222 such that an ultraviolet (UV) radiation source 228 such as anultraviolet bulb or an array of ultraviolet LEDs are positioned betweenpairs of active cell panels 224. Each UV radiation source 228 isconfigured to emit UV radiation toward the surfaces of adjacent activecell panels 224.

The UV radiation, on its own, kills or destroys biological pollutantsvia ultraviolet germicidal irradiation (UVGI). Additionally, the UVradiation energizes the photocatalytic oxidative coating or surfaces ofthe active cell panels 224. The UV energized photocatalytic coatinginteracts with the oxygen molecules within the air/vapor mixture toproduce ozone which in turn interacts with the water molecules withinthe air/vapor mixture to produce hydrogen peroxide, oxidative hydroxylradicals (OH), and super ions (O₂ with an extra electron) (hereinafterreferred to as “oxidative molecules”). The oxidative molecules interactwith contaminants that are airborne with in the air/vapor mixture tooxidize them or “burn them” chemically in order to neutralize or renderthem benign.

The air/vapor mixture 210 becomes treated air/vapor mixture 230 as itmoves or flows through the treatment chamber 216. The treated air/vapormixture 230 comprises air, reduced or controlled amounts ofcontaminants, benign contaminants, ozone in amounts between 0.001 ppmand 0.007 ppm, hydrogen peroxide in amounts between about 0.25 ppm and0.45 ppm, hydroxyl radicals, super ions and humidity in a range betweenabout 75% and 100%. Additionally, the treated air/vapor mixture 230 maybe warmer in temperature than the temperature of the intake air 202. Thetreated air/vapor mixture 230 exits the treatment chamber 216 by way ofan output passage 232. In various embodiments the output passage 232 hasa cross sectional area perpendicular to the general treated air/vapormixture flow direction that is ½ to 1/30^(th) of a cross-sectional areatreatment chamber 216 that is perpendicular to the general flowdirection.

In various embodiments the active cell panels may have variousconfigurations. For example, they may have a corrugated or fan-foldcross section in order to increase the surface area that UV radiationfrom a UV source has to impinge upon. Additionally, the panels may bemade of a woven, braided, mesh, screen, or layered corrugated structuresthat are coated with the photocatalytic material and having aperturesthere-through. In yet other embodiments, the surface of the active cellpanels may be covered with randomly spaced or arrays of pyramid, coneshaped, or other tapered polyhedron-like shapes in order to maximize thecoated surface area facing the UV radiation source that can beirradiated by the UV radiation.

FIG. 4 is a perspective view and example of an active cell panel 300that may be incorporated into various embodiments. The active cell panel300 has a length L, width W, and thickness T. Apertures 302 can bearranged in multiple rows and in a somewhat honeycomb-like structurethat establishes an array of apertures or tube-like structures. Eachaperture 302 may extend in a transverse and/or diagonal fashion acrossor through the thickness T of the active cell panel 300 from a frontside to a back side. As an example, each of the apertures 302 may extendtransversely at about 45° (plus or minus 20°) with respect to a front orback surface of the active cell panel 300. This also is shown in FIG. 2,elements 138 b and 138 c as well as in FIG. 3, elements 224 and 224′wherein examples of the active panels are shown in cross-section.

By providing the apertures 302 extending transversely and diagonallythrough the thickness of an active cell panel 300, more surface areahaving a photocatalytic oxidative coating is exposed to UV radiationemanating from one or more UV radiation sources and/or reflected off ofreflective surfaces within the treatment chamber. The greater thephotocatalytic coated surface area exposed to UV radiation, the moreefficient the photocatalytic oxidative process is and the greater theamount of ozone, hydrogen peroxide, hydroxyl radicals and super ionscreated. With more oxidative molecules being created, more efficientembodiments of an ECT apparatus can be realized.

Referring now to FIG. 5, the method of controlling or reducingcontaminants in accordance with various embodiments of the invention isprovided. At step 400, within a closed or semi closed environment, airhaving airborne contaminants therein is extracted from the environmentvia an intake passage and blown into an embodiment of an ECT apparatus.The contaminant containing air intake air may contain variouscontaminants including pathogens, allergens and/or odor-causing agentssuch as VOCs in amounts that are unwanted or considered an irritant ordangerous to humans or other animals in the environment. In somemethods, at step 402 a mechanical or electronic air filter may be usedto filter particles larger than a predetermined size from the intake airas it enters an intake passage of the ECT apparatus. At step 404, a fanor blower device may be used to help extract contaminant laden air fromthe environment outside the ECT apparatus and push the contaminant ladenair, as intake air, into the workings of the ECT apparatus embodiment.

In some embodiments, at step 405 the intake air is heated by a heatingdevice. At step 406 the heated air is sensed by an air temperaturesensing device which provides an input temperature signal to amicrocontroller and/or temperature feedback such that the heating deviceat step 405 can be adjusted. Embodiments may heat the intake air to atemperature such that the intake air can hold water vapor for watermolecules without becoming saturated. Various embodiments heat theintake air with the heating device to the temperature such that theintake air can hold humidity at from between 75 to 100% without thewater molecules being saturated in the intake air and condensing withinembodiments of the ECT apparatus.

In some embodiments, at step 407 a humidifier that is controlled by acontroller produces water vapor or fine water droplets at a rate, whichwhen added to the heated intake air will increase the humidity of theintake air to between 75% and 100% humidity.

Alternatively, in embodiments that do not incorporate a heating devicethat heats the intake air at step 405, then at step 406 the temperatureof the intake air is sensed by the temperature sensing device, whichprovides a temperature signal to a controller. The controllerdetermines, using the temperature signal along with perhaps a pressuresignal, the amount of water vapor that can be added to the intake air inorder to increase the relative humidity to between 75% and 100%.

At step 408 the water vapor or water mist/droplets from the humidifierare added to the intake air thereby creating an intake air/vapormixture. This air vapor mixture may be mixed at step 410 within theintake passage by a static mixer device in order to make the air/vapormixture more homogeneous and/or to help water droplets evaporate intowater vapor. At step 412 the humidity of the air/vapor mixture may besensed by a humidity sensing device, which provides a humidity signalrepresentative of the sensed humidity back to the controller asfeedback. As a result the controller may adjust the rate that the watervapor is added to the intake air so that the humidity or relativehumidity of the air/vapor mixture is close to a predetermined value thatis between 75% and 100% humidity or relative humidity.

At step 416, the air/vapor mixture is subjected to UV radiation andphotocatalytic oxidation within a treatment chamber. Ultraviolet (UV)radiation sources emit UV radiation through the air/vapor mixture andonto surfaces of active cell panels wherein the photocatalytic oxidationprocess occurs. The combination of the UV radiation impinging throughthe air/vapor mixture and onto the photocatalytic surfaces on the activecell panels, along with the high level of humidity within the treatmentchamber produces an abundance of various oxidizing molecules includingozone, hydrogen peroxide, hydroxyl radicals, and super ions. Theoxidizing molecules interact with contaminants within the air/vapormixture.

Within the treatment chamber there may also be reflective surfacesand/or additional static mixing elements such as flaps or fins. Thereflective surfaces are angled to reflect UV radiation from, forexample, the sides of the treatment chamber back through the air/vapormixture and toward the active cell panels to help maximize the oxidativeprocess. The static mixing elements may help further stir or mix theair/vapor mixture as it moves through the treatment chamber in order tohelp maximize photocatalytic interaction of the air/vapor mixture'smolecules with oxidative molecules produced by the photocatalyticoxidative reactions between the UV radiation, the water vapor, and thephotocatalytic surfaces of the active cell panels.

At step 418 the oxidizing reaction between the oxidizing molecules andmany of the contaminants with in the air/vapor mixture, reduce, control,kill and render the contaminants benign within the treatment chamberthereby treating the air/vapor mixture. The treated air/vapor mixture,at step 420, exits the treatment chamber through an output passage. Invarious embodiments the output passage may include an output fan orblower device to help force the treated air/vapor mixture into theclosed or semi-closed environment from which the intake air may haveoriginated. At the moment of being output, the treated air/vapor mixturecomprises air, benign contaminants, contaminants, ozone at aconcentration between about 0.001 and 0.007 ppm, hydrogen peroxide at aconcentration between about 0.25 and 0.45 ppm, hydroxyl radicals, superions, and having a humidity or relative humidity of between about 75%and 100%.

After the treated air/vapor mixture is output from the output passage,it may contain residual amounts of oxidizers that may further oxidizecontaminants both within the treated air/vapor mixture, airborne withinthe closed or semi-enclosed environment, and/or contaminants on surfaceswithin the closed or semi-enclosed environment.

The foregoing description and examples are illustrative only and are notintended to limit the scope of the invention as defined by the appendedclaims. It will be apparent to those skilled in the art that variousmodifications and variations can be made to the present inventionembodiments without departing from the novelty and usefulness of theinvention. Thus, it is intended that the present description covers themultiple modifications and variations of this invention provided theyare within the scope of the appended claims and their equivalents.

It is further appreciated by those skilled in the art having the benefitof this disclosure that this method and device for enhancing thereduction of pathogens, allergens and odor-causing agents provides botha method and apparatus for reducing and/or helping the prevention ofinfections as well as controlling and/or reducing the level of one ormore pathogens, allergens, and/or odor-causing agents that are airbornewithin a closed or semi-closed environment or that are on the surfacesof objects within the closed or semi-closed environment. It should beunderstood that the drawings and detailed description herein are to beregarded in an illustrative rather than in a restrictive manner, and arenot drawn to scale or intended to limit the particular forms andexamples disclosed. On the contrary, included are further modifications,changes, rearrangements, substitutions, alternatives, design choices,and embodiments apparent to those of ordinary skill in the art, withoutdeparting from the novelty, functionality and usefulness hereof, asdefined by the following claims. Thus, it is intended that the followingclaims be interpreted to embrace all such further modifications,changes, rearrangements, substitutions, alternatives, design choices,and embodiments.

1. A system that reduces a level of substances in air within anenvironment, wherein the environment comprises a closed or partiallyopen environment and wherein the substances are selected from the groupconsisting of pathogens, allergens, and odor-causing agents, the systemcomprising: an inlet passage configured to receive inlet air from theenvironment; a humidifier input configured to receive water vapor from ahumidification device; a mixer portion where the inlet air and watervapor are mixed to form an air/vapor mixture; a controller in operativecommunication with the humidification device; a humidity sensorconfigured to sense the humidity level of the air/vapor mixture, thecontroller being configured to adjust operation of the humidificationdevice based on the sensed humidity level so as to bring the humiditylevel of the air/vapor mixture to about 70 percent to about 100 percent;and a treatment chamber wherein the air/vapor mixture is subject to aphotocatalytic oxidation treatment, the treatment chamber including oneor more ultraviolet light sources and including photocatalytic materialconfigured to receive ultraviolet light emitted from the one or moreultraviolet light sources.
 2. The system of claim 1, wherein thetreatment chamber comprises at least one active cell panel, the activecell panel being at least partially coated in the photocatalyticmaterial.
 3. The system of claim 2, wherein the at least one active cellpanel comprises a plurality of apertures disposes in a transverse mannerfrom a first side of the active cell to a second side of the activecell, and wherein the apertures are at least partially coated with thephotocatalytic material.
 4. The system of claim 2, wherein the at leastone active cell panel extends inward into the treatment chamber from aside wall of the treatment chamber.
 5. The system of claim 2, wherein aplurality of active cell panels are included in the treatment chamber,and wherein the active cell panels are positioned approximately parallelwith each other.
 6. The system of claim 1, further comprising a blowerproximate to the inlet passage for pushing inlet air from theenvironment into the inlet passage.
 7. The system of claim 1, whereinthe mixer portion comprises a static mixer.
 8. The system of claim 1,wherein the controller is configured to adjust operation of thehumidification device to bring the humidity level of the air/vapormixture to between about 75 percent and about 100 percent.
 9. The systemof claim 1, further comprising an outlet passage configured to allowtreated air/vapor to exit the treatment chamber and be distributed intothe environment.
 10. The system of claim 9, wherein the treatmentchamber and the outlet passage are sized so that an average velocity ofthe air/vapor within the treatment chamber is between 5 and 100 timesslower than the average velocity of the air/vapor within the outletpassage.
 11. The system of claim 1, wherein the treatment chamberfurther comprises an airlock configured to allow the introduction andremoval of an object to be decontaminated.
 12. The system of claim 1,further comprising a heater configured to heat the inlet air and/or theair/vapor mixture.
 13. The system of claim 12, further comprising atemperature sensor configured to sense the temperature of the inlet airand/or the air/vapor mixture.
 14. The system of claim 13, wherein thecontroller is also in operative communication with the heater and isconfigured to adjust operation of the heater and the humidificationdevice to bring the humidity level of the air/vapor mixture to betweenabout 70 percent and about 100 percent.
 15. The system of claim 1,wherein the treatment chamber and the inlet passage are sized to allowthe air/vapor mixture to slow down in velocity within the treatmentchamber as compared to a velocity through the inlet passage.
 16. Thesystem of claim 1, wherein the treatment chamber further comprises oneor more ultraviolet radiation reflective surfaces to reflect ultravioletradiation emitted from the one or more ultraviolet light sources anddirect it toward the photocatalytic material.
 17. A method of reducing asubstance level in air within an environment, wherein the environmentcomprises a closed or partial open environment and wherein the substancelevel comprises substances selected from a contaminate group consistingof pathogens, allergens, and odor-causing agents, the method comprising:receiving air from the environment into an inlet of a treatment system,the air having an initial level of contaminates; mixing the received airwith water vapor to achieve an air/vapor mixture having a humidity levelof about 70 percent to about 100 percent; treating the air/vapor mixturein a treatment chamber, wherein treating comprises: directing, using anultraviolet light source, ultraviolet light on one or morephotocatalytic surfaces within the treatment chamber, and generatingreactive oxidizing species that oxidize or decompose the substances suchthat the contaminate level in the treatment chamber is reduced.
 18. Themethod of claim 17, further comprising outputting the treated air/vapormixture back into the environment such that residual amounts of thereactive oxidizing species continue to oxidize or decompose contaminatesin the air or on surfaces within the environment until the residualamounts of the reactive oxidizing species disassociate.
 19. The methodof claim 17, wherein the reactive oxidizing species in the air/vapormixture within the treatment chamber comprise about 0.0001 to 0.0070 ppmozone and about 0.25 to 0.45 ppm hydrogen peroxide.
 20. The method ofclaim 19, wherein the reactive oxidizing species in the air/vapormixture within the treatment chamber also comprises hydroxyl radicalsand super ions.